ggplot geom_bar() customize by linetype and fill

Question

I am using ggplot2 and geom_bar() to plot some statistics. Is there a way to customize the fillings in the bar, and the line type for each of the bars? I would like to highlight two key features: There are five bars overall and the numbers they represent are produced from two different types of input, and use three different functions I use for the plot. The bars should show the function, input variation. I thought of using full dark fill for one set of inputs, and white fill for the other set of inputs. For the functions, I could use different line types to show the contrast.

In summary the values from the bar represent outputs from combination of inputs X and Y on functions f1, f2, and f3: bar A: input X function f1; bar B input Y function f1; bar C input X function f2; bar D input Y function f2; bar E input Y function f3.

Any suggestions on how this could be possible? Here is an example I was able to try, but as you see it is not complete to what I want to achieve where I fill subcompact and midsize with a color, but how could I change the line type? and how could I use geom_text() for the text:

      library(ggplot2)
      data(mpg)
      unique(mpg$class)
      library(ggplot2)

     ggplot(mpg, aes(x = class, fill = class %in% c("subcompact", "midsize"))) +
geom_bar(linetype="dashed", colour="darkgreen") + scale_fill_grey() + guides(fill=FALSE) + theme_classic()

Answer 1

Here is an example with three arbitrary (and arguable) classifications. Note use of dplyr to define the groups first to make the legends more easily. I am assuming that in most use cases, you would have (or could construct) columns similar to mine here with your data of interest.

I am note sure why you would want to do this for this type of graph, but none the less, it is certainly possible.

Note that I had to muck around with the linetype legend a little to make it display nicely.

ggplot(mpg %>%
         mutate(`Small Car` = class %in% c("subcompact", "midsize")
                , `Stuff Hauler` = class %in% c("pickup", "suv")
                , `Uncomfortable for long drive` = class %in% c("compact", "pickup", "2seater")
                )
       , aes(x = class
             , fill = `Small Car`
             , linetype = `Stuff Hauler`
             , col = `Uncomfortable for long drive`
             )) +
  geom_bar(size = 2) +
  scale_fill_grey() +
  theme_classic() +
  guides(linetype = guide_legend(override.aes = list(fill = NA
                                                     , col = "black")))